Many electric motors are commutated by switching the current applied to the commutator of a motor using two or more brushes that contact the commutator. Typically, brush holder assemblies are mounted to the electric motor to hold the brushes in electrical contact with the commutator. A spring is included in each brush holder assembly to exert a force on the brush to maintain contact between the brush and the commutator.
In some motors, the brush holder assemblies are molded into the sleeve and/or endcap of the motor. In other motors, the brush holder assemblies are mounted to the electric motor. During manufacture of the electric motor, it is necessary to place a brush and spring into each brush holder assembly. It is further necessary to electrically connect each brush to a source of electrical current.
In some applications, the useful life of the brushes is exceeded before the useful life of the motor is reached. For example, the friction between the brushes and the commutator can result in wearing of the brushes over time and decreased performance. It may therefore be desirable to provide access to the brushes in the brush holder assemblies so that the brushes can be periodically replaced.